/*******************************************************************************
* 文件名		: mlx90614.c
* 作  者	: 
* 版  本	: 
* 日  期	: 2013-08-07
* 描  述	: mlx90614函数
PB6：SCL
PB7：SDA
在主函数中先初始化SMBus_Init();
需要读取温度就调用temp=SMBus_ReadTemp();  //读取温度，temp是浮点数，转整数：i=ceil(temp); 
*******************************************************************************/

/* Includes ------------------------------------------------------------------*/

#include "mlx90614.h"
#include <stdio.h>
#include <unistd.h>
#include "ohos_init.h"
#include "cmsis_os2.h"

#include <hi_types_base.h>
#include <hi_early_debug.h>
#include "hi_time.h"
#include "iot_gpio.h"
#include "hi_io.h"
#include "iot_i2c.h"

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
#define ACK	 0 //应答
#define	NACK 1 //无应答
#define SA				0x00 //Slave address 单个MLX90614时地址为0x00,多个时地址默认为0x5a
#define RAM_ACCESS		0x00 //RAM access command RAM存取命令
#define EEPROM_ACCESS	0x20 //EEPROM access command EEPROM存取命令
#define RAM_TOBJ1		0x07 //To1 address in the eeprom 目标1温度,检测到的红外温度 -70.01 ~ 382.19度

#define SMBUS_SCK		0
#define SMBUS_SDA		1


#define SMBUS_SCK_H()	    IoTGpioSetOutputVal(SMBUS_SCK,IOT_GPIO_VALUE1) //置高电平
#define SMBUS_SCK_L()	    IoTGpioSetOutputVal(SMBUS_SCK,IOT_GPIO_VALUE0)  //置低电平
#define SMBUS_SDA_H()	    IoTGpioSetOutputVal(SMBUS_SDA,IOT_GPIO_VALUE1)
#define SMBUS_SDA_L()	    IoTGpioSetOutputVal(SMBUS_SDA,IOT_GPIO_VALUE0)




/**************************************GXY*******************************************/
//IO方向设置
#define SMBUS_SDA_IN()  {IoTGpioSetDir(SMBUS_SDA,IOT_GPIO_DIR_IN);hi_udelay(1);}	//PB11输入模式
#define SMBUS_SDA_OUT() {IoTGpioSetDir(SMBUS_SDA,IOT_GPIO_DIR_OUT);hi_udelay(1);} //PB11输出模式



/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/

/*******************************************************************************
* Function Name  : SMBus_StartBit
* Description    : Generate START condition on SMBus
* Input          : None
* Output         : None
* Return         : None
*******************************************************************************/
void SMBus_StartBit(void)
{
    SMBUS_SDA_OUT();
    SMBUS_SDA_H();		// Set SDA line
    SMBus_Delay(10);	    // Wait a few microseconds
    SMBUS_SCK_H();		// Set SCL line
    SMBus_Delay(10);	    // Generate bus free time between Stop
    SMBUS_SDA_L();		// Clear SDA line
    SMBus_Delay(10);	    // Hold time after (Repeated) Start
    // Condition. After this period, the first clock is generated.
    //(Thd:sta=4.0us min)在SCK=1时，检测到SDA由1到0表示通信开始（下降沿）
    SMBUS_SCK_L();	    // Clear SCL line
    SMBus_Delay(10);	    // Wait a few microseconds
}

/*******************************************************************************
* Function Name  : SMBus_StopBit
* Description    : Generate STOP condition on SMBus
* Input          : None
* Output         : None
* Return         : None
*******************************************************************************/
void SMBus_StopBit(void)
{
    SMBUS_SDA_OUT();
    SMBUS_SCK_L();		// Clear SCL line
    SMBus_Delay(10);	    // Wait a few microseconds
    SMBUS_SDA_L();		// Clear SDA line
    SMBus_Delay(10);	    // Wait a few microseconds
    SMBUS_SCK_H();		// Set SCL line
    SMBus_Delay(10);	    // Stop condition setup time(Tsu:sto=4.0us min)
    SMBUS_SDA_H();		// Set SDA line在SCK=1时，检测到SDA由0到1表示通信结束（上升沿）
}

/*******************************************************************************
* Function Name  : SMBus_SendByte
* Description    : Send a byte on SMBus
* Input          : Tx_buffer
* Output         : None
* Return         : None
*******************************************************************************/
uint8_t SMBus_SendByte(uint8_t Tx_buffer)
{
    //printf("Enter SMBus_SendByte\n");
    uint8_t	Bit_counter;
    uint8_t	Ack_bit;
    uint8_t	bit_out;

    for(Bit_counter=8; Bit_counter; Bit_counter--)
    {
        if (Tx_buffer&0x80)
        {
            bit_out=1;   // If the current bit of Tx_buffer is 1 set bit_out
        }
        else
        {
            bit_out=0;  // else clear bit_out
        }
        SMBus_SendBit(bit_out);		// Send the current bit on SDA
        Tx_buffer<<=1;				// Get next bit for checking
    }

    Ack_bit=SMBus_ReceiveBit();		// Get acknowledgment bit
    return	Ack_bit;
}

/*******************************************************************************
* Function Name  : SMBus_SendBit
* Description    : Send a bit on SMBus 82.5kHz
* Input          : bit_out
* Output         : None
* Return         : None
*******************************************************************************/
void SMBus_SendBit(uint8_t bit_out)
{
    SMBUS_SDA_OUT();
    if(bit_out==0)
    {
        SMBUS_SDA_L();
    }
    else
    {
        SMBUS_SDA_H();
    }
    SMBus_Delay(4);					// Tsu:dat = 250ns minimum
    SMBUS_SCK_H();					// Set SCL line
    SMBus_Delay(12);					// High Level of Clock Pulse
    SMBUS_SCK_L();					// Clear SCL line
    SMBus_Delay(6);					// Low Level of Clock Pulse
//	SMBUS_SDA_H();				    // Master release SDA line ,
    return;
}

/*******************************************************************************
* Function Name  : SMBus_ReceiveBit
* Description    : Receive a bit on SMBus
* Input          : None
* Output         : None
* Return         : Ack_bit
*******************************************************************************/
uint8_t SMBus_ReceiveBit(void)
{
    uint8_t Ack_bit;
    IotGpioValue SMBUS_sda_val = IOT_GPIO_VALUE0;
    SMBUS_SDA_OUT();
    SMBUS_SDA_H();          //引脚靠外部电阻上拉，当作输入
    SMBus_Delay(4);			// High Level of Clock Pulse
    SMBUS_SCK_H();			// Set SCL line
    SMBus_Delay(10);			// High Level of Clock Pulse
    SMBUS_SDA_IN();
    IoTGpioGetOutputVal(SMBUS_SDA,&SMBUS_sda_val);
    if (SMBUS_sda_val)
    {
        Ack_bit=1;
    }
    else
    {
        Ack_bit=0;
    }
    SMBUS_SCK_L();			// Clear SCL line
    SMBus_Delay(6);			// Low Level of Clock Pulse

    return	Ack_bit;
}

/*******************************************************************************
* Function Name  : SMBus_ReceiveByte
* Description    : Receive a byte on SMBus
* Input          : ack_nack
* Output         : None
* Return         : RX_buffer
*******************************************************************************/
uint8_t SMBus_ReceiveByte(uint8_t ack_nack)
{
    uint8_t RX_buffer;
    uint8_t	Bit_Counter;

    for(Bit_Counter=8; Bit_Counter; Bit_Counter--)
    {
        if(SMBus_ReceiveBit())			// Get a bit from the SDA line
        {
            RX_buffer <<= 1;			// If the bit is HIGH save 1  in RX_buffer
            RX_buffer |=0x01;
        }
        else
        {
            RX_buffer <<= 1;			// If the bit is LOW save 0 in RX_buffer
            RX_buffer &=0xfe;
        }
    }
    SMBus_SendBit(ack_nack);			// Sends acknowledgment bit
    return RX_buffer;
}

/*******************************************************************************
* Function Name  : SMBus_Delay
* Description    : 延时  一次循环约1us
* Input          : time
* Output         : None
* Return         : None
*******************************************************************************/
void SMBus_Delay(uint16_t time)
{
    hi_udelay(time);
}

/*******************************************************************************
* Function Name  : SMBus_Init
* Description    : SMBus初始化
* Input          : None
* Output         : None
* Return         : None
*******************************************************************************/
void SMBus_Init()
{

    hi_io_set_func(SMBUS_SDA, HI_IO_FUNC_GPIO_1_GPIO);
    hi_io_set_func(SMBUS_SCK, HI_IO_FUNC_GPIO_0_GPIO);
    IoTGpioInit(SMBUS_SDA);
    IoTGpioInit(SMBUS_SCK);
    hi_io_set_pull(SMBUS_SDA,HI_IO_PULL_UP);
    hi_io_set_pull(SMBUS_SCK,HI_IO_PULL_UP);

    IoTGpioSetDir(SMBUS_SDA,IOT_GPIO_DIR_OUT);
    IoTGpioSetDir(SMBUS_SCK,IOT_GPIO_DIR_OUT);


    SMBUS_SCK_H();
    SMBUS_SDA_H();

}

/*******************************************************************************
 * Function Name  : SMBus_ReadMemory
 * Description    : READ DATA FROM RAM/EEPROM
 * Input          : slaveAddress, command
 * Output         : None
 * Return         : Data
*******************************************************************************/
uint16_t data;			// Data storage (DataH:DataL)
uint8_t DataL=0;			// Low data byte storage
uint8_t DataH=0;			// High data byte storage

uint16_t SMBus_ReadMemory(uint8_t slaveAddress, uint8_t command)
{

    uint8_t Pec;				// PEC byte storage

    uint8_t arr[6];			// Buffer for the sent bytes
    uint8_t PecReg;			// Calculated PEC byte storage
    uint8_t ErrorCounter;	// Defines the number of the attempts for communication with MLX90614

    ErrorCounter=0x00;				// Initialising of ErrorCounter
    slaveAddress <<= 1;	//2-7位表示从机地址

    do
    {
        repeat:
        SMBus_StopBit();			    //If slave send NACK stop comunication
        --ErrorCounter;				    //Pre-decrement ErrorCounter
        if(!ErrorCounter) 			    //ErrorCounter=0?
        {
            break;					    //Yes,go out from do-while{}
        }
        SMBus_StartBit();				//Start condition
        if(SMBus_SendByte(slaveAddress))//Send SlaveAddress 最低位Wr=0表示接下来写命令
        {
            goto	repeat;			    //Repeat comunication again
        }
        if(SMBus_SendByte(command))	    //Send command
        {
            goto	repeat;		    	//Repeat comunication again
        }
        SMBus_StartBit();					//Repeated Start condition
        if(SMBus_SendByte(slaveAddress+1))	//Send SlaveAddress 最低位Rd=1表示接下来读数据
        {
            goto	repeat;             	//Repeat comunication again
        }

        DataL = SMBus_ReceiveByte(ACK);	//Read low data,master must send ACK
        DataH = SMBus_ReceiveByte(ACK); //Read high data,master must send ACK
        Pec = SMBus_ReceiveByte(NACK);	//Read PEC byte, master must send NACK
        SMBus_StopBit();				//Stop condition

        arr[5] = slaveAddress;		//
        arr[4] = command;			//
        arr[3] = slaveAddress+1;	//Load array arr
        arr[2] = DataL;				//
        arr[1] = DataH;				//
        arr[0] = 0;					//
        PecReg=PEC_Calculation(arr);//Calculate CRC
    }
    while(PecReg != Pec);		//If received and calculated CRC are equal go out from do-while{}
    data = (DataH<<8) | DataL;	//data=DataH:DataL
    return data;
}

/*******************************************************************************
* Function Name  : PEC_calculation
* Description    : Calculates the PEC of received bytes
* Input          : pec[]
* Output         : None
* Return         : pec[0]-this byte contains calculated crc value
*******************************************************************************/
uint8_t PEC_Calculation(uint8_t pec[])
{
    uint8_t 	crc[6];
    uint8_t	BitPosition=47;
    uint8_t	shift;
    uint8_t	i;
    uint8_t	j;
    uint8_t	temp;
    do
    {
        /*Load pattern value 0x000000000107*/
        crc[5]=0;
        crc[4]=0;
        crc[3]=0;
        crc[2]=0;
        crc[1]=0x01;
        crc[0]=0x07;

        /*Set maximum bit position at 47 ( six bytes byte5...byte0,MSbit=47)*/
        BitPosition=47;

        /*Set shift position at 0*/
        shift=0;

        /*Find first "1" in the transmited message beginning from the MSByte byte5*/
        i=5;
        j=0;
        while((pec[i]&(0x80>>j))==0 && i>0)
        {
            BitPosition--;
            if(j<7)
            {
                j++;
            }
            else
            {
                j=0x00;
                i--;
            }
        }/*End of while */

        /*Get shift value for pattern value*/
        shift=BitPosition-8;

        /*Shift pattern value */
        while(shift)
        {
            for(i=5; i<0xFF; i--)
            {
                if((crc[i-1]&0x80) && (i>0))
                {
                    temp=1;
                }
                else
                {
                    temp=0;
                }
                crc[i]<<=1;
                crc[i]+=temp;
            }/*End of for*/
            shift--;
        }/*End of while*/

        /*Exclusive OR between pec and crc*/
        for(i=0; i<=5; i++)
        {
            pec[i] ^=crc[i];
        }/*End of for*/
    }
    while(BitPosition>8); /*End of do-while*/

    return pec[0];
}

/*******************************************************************************
* Function Name  : SMBus_ReadTemp
* Description    : Calculate and return the temperature
* Input          : None
* Output         : None
* Return         : SMBus_ReadMemory(0x00, 0x07)*0.02-273.15
*******************************************************************************/
float SMBus_ReadTemp(void)
{
    float temp;
    temp = SMBus_ReadMemory(SA, RAM_ACCESS|RAM_TOBJ1)*0.02-273.15;
    return temp;
}

/*********************************END OF FILE*********************************/
